This application is to request funds to purchase the Olympus IV-100 single-photon laser scanning confocal system designed for deep-tissue fluorescent imaging in live animals. Utilizing high numerical aperture microprobe optical lenses accurately corrected for lateral and axiochromatic aberrations, the IV-100 provides solutions to hitherto challenging problems of imaging cellular events in multiple organs of the same animals by combining the following key features in one instrument: (1) Direct access of miniaturized optical probe to well-buried internal organs through minimally invasive surgical incisions, (2) Z-sectioning and three-dimensional rendering of the specimen through adjustable confocal aperture, (3) region of interest laser scanning, (4) the choice of sequential scan mode to eliminate emission crosstalk between fluorophores, (5) fully integrated and optimized light path to take advantage of the superior penetration depth and low autofluorescence window of near-infrared imaging, (6) single cell resolution, (7) multi-color fluorescent probe for multi-parametric imaging, and (8) high signal-to- noise ratio, ultra low pixilation imaging compared to other microendoscopes. This instrument thus allows users to simultaneously monitor biological events at the cellular levels, in hard-to- access organs within the same animals at various time points. The Northwestern University Cell Imaging Facility was selected by Olympus to be one of the three national advance placement sites to evaluate this instrument. We not only took advantage of this opportunity to gain unique expertise in this novel imaging technique, but made numerous constructive suggestions for Olympus to further improve this instrument to suit the need of a multitude of experimental applications. We are now well-positioned to reap the maximum benefits from the IV-100, and to help advance the methodology of small animal imaging. [unreadable] Relevance: The Olympus IV-100 is potentially a paradigm-shaping instrument that will greatly enhance the experimental repertoire of many translational research projects such as in the studies of cancer metastasis, angiogenesis, disease progression, as well as in testing the efficacy of various drug treatments. Its ability to perform optical-sectioning in live specimens through minimally invasive incisions offers investigators an unprecedented ability to examine various biological structures in three dimensions at multiple time points. The IV-100 is a vital instrument for characterizing the architecture of engrafted scaffolding to promote cell growth, nano-materials designed for drug delivery, and also the extent of immuno-rejection; it will significantly accelerate the fields of tissue engineering, drug delivery and bio-nanotechnology. [unreadable] [unreadable] [unreadable]